Gentoo Archives: gentoo-project

From: desultory <desultory@g.o>
To: gentoo-project@l.g.o, "Michał Górny" <mgorny@g.o>
Subject: Re: [gentoo-project] pre-GLEP: Gentoo OpenPGP web of trust
Date: Sat, 02 Feb 2019 05:55:10
Message-Id: fc39280f-3175-aaae-804d-29d65a6826f0@gentoo.org
On 01/31/19 08:56, Michał Górny wrote:
> Hello, > > Here's first draft of proposed GLEP for establishing a WoT inside > Gentoo. It already incorporates some early feedback, so before you > start the usual shooting: making it obligatory wasn't my idea. >
Have some faith in your fellow developers, most don't tend to communicates in ad hominem. Also, have some faith in yourself, it is not a bad idea just because you posted it, it is a bad idea on it's own (lack of) merit.
> --- > > --- > GLEP: 9999 > Title: Gentoo OpenPGP web of trust > Author: Michał Górny <mgorny@g.o> > Type: Standards Track > Status: Draft > Version: 1 > Created: 2019-01-20 > Last-Modified: 2019-01-31 > Post-History: 2019-01-31 > Content-Type: text/x-rst > --- > > Abstract > ======== > > In this GLEP the current status of establishing an OpenPGP web of trust > between Gentoo developers is described, and an argument is made for > pushing it forward. Advantages of a strong WoT are considered, > including its usefulness for sign-off real name verification. Rules for > creating key signatures are established, and an example of signing > procedure is provided. > > > Motivation > ========== > > While Gentoo observes the status of OpenPGP web of trust for many years, > there never has been a proper push to get all developers covered by it > or even formalize the rules of signing one another's keys. Apparently, > there are still many Gentoo developers who do not have their > ``@gentoo.org`` UID signed by another active developer. Historically > there were also cases of developers signing others' UIDs without > actually verifying their identity. [#WOT-GRAPH]_ [#WOT-STATS]_ >
I have been affiliated with Gentoo for over a decade now, I have never needed to use my GPG keys for anything beyond verifying that they worked. I have never needed to have them signed by anyone or anything that wasn't automated. In over a decade.
> The web of trust is usually considered secondary to Gentoo's internal > trust system based on key fingerprints stored in LDAP and distributing > via the website. While this system reliably covers all Gentoo > developers, it has three major drawbacks: > > 1. It is entirely customary and therefore requires customized software > to use. In other words, it's of limited usefulness to people outside > Gentoo or does not work out of the box there. >
The custom software is, as one might infer, already in existence and already operating, and has been for some time. Th role of the software in question is to be *internally* useful, being useful to third parties is outside of the problem space it is meant to address.
> 2. At least in the current form, it is entirely limited to Gentoo > developers. As such, it does not facilitate trust between them > and the outer world. >
Which is entirely in keeping with its design and intended use; in short, this not a bug..
> 3. It relies on a centralized server whose authenticity is in turn > proved via PKI. This model is generally considered weak. >
However weak you may consider it to be, it has been sufficient for its purpose for quite some time.
> Even if this trust system is to stay being central to Gentoo's needs, > it should be beneficial for Gentoo developers start to improving > the OpenPGP web of trust, both for the purpose of improving Gentoo's > position in it and for the purpose of enabling better trust coverage > between Gentoo developers, users and other people. >
And this is where things really start to go off the rails: "improving Gentoo's position in" the web of trust rather strongly implies a deep misunderstanding of how the system works and why it works the way it does. Gaming a system that you do not understand is not likely to go well.
> Furthermore, the recent copyright policy established in GLEP 76 > introduces the necessity of verifying real names of developers. Given > that the Foundation wishes to avoid requesting document scans or other > form of direct verification, the identity verification required > for UID signing can also serve the needs of verifying the name > for Certificate of Origin sign-off purposes. [#GLEP76]_ >
No, it doesn't. GLEP 76 makes the assertion that "The sign-off must contain the committer's legal name as a natural person, i.e., the name that would appear in a government issued document.", it does not prescribe institutional confirmation of that "legal name as a natural person". The implication is, at least if one is to read the document as written, that the individual signing off on the commit is affirming that they are using their "legal name as a natural person".
> > Specification > ============= > > Signature requirements > ---------------------- > > As a final goal of this GLEP, each Gentoo developer will be required > to have at least one signature from another Gentoo developer or from > member of one of the partner communities present on their > ``@gentoo.org`` UID. > > Recruits will be required to obtain such a signature on one of their > user identifiers containing their real name before becoming Gentoo > developers. After obtaining the ``@gentoo.org`` e-mail address, they > will be required to add it to their OpenPGP key and obtain a signature > on it as well before obtaining commit access (this requires only e-mail > exchange with previous signer). > > Transitional (grandfathering) period will be provided based on two > milestones: > > - newly joining developers will be required to have their key signed > prior to joining starting 2019-10-01, > > - all existing developers will be required to have their key signed > starting 2020-07-01. > > If necessity arises, the Council may defer the milestones and extend > the transitional period. > > > Key signing rules > ----------------- > > When signing an OpenPGP key belonging to another person, the following > rules need to be respected: > > 1. Sign only those user identifiers which you have successfully > verified. Do not sign all identifiers unless you have previously > verified all of them. >
This seems to logically conflict with point 4.
> 2. For the purpose of Gentoo sign-off usage, the key must have > an identifier consisting of the real name of a natural person > (per GLEP 76) and the respective e-mail address to be used > in ``Signed-off-by`` line. In case of Gentoo developers, this e-mail > address has to be their ``@gentoo.org`` address. > > Other user identifiers do not need to strictly follow those rules, > and may be skipped for the purpose of Gentoo key signing. However, > you should follow the respective rules for verifying those kind > of identifiers (e.g. XMPP UIDs should be signed after verifying > the working XEP-0373 or similar encryption, keybase.io UIDs should > follow appropriate keybase verification). [#XEP-0373]_ > [#KEYBASE.IO]_ > > 3. Before signing a user identifier, make sure to: > > a. Obtain a fingerprint of the person's primary key (for the purpose > of verifying the authenticity of the key you're about to sign). > Usually, a printed strip containing ``gpg --list-key`` output > is used for this purpose. > > b. Verify the person's real name (at least for the user identifier > used for copyright purposes). This is usually done through > verifying an identification document with photograph. It is > a good idea to ask for the document type earlier, and read on > forgery protections used. >
Are you, in the general sense regarding the authors of this proposal, seriously suggesting that random developers should become self-educated expert identity document verifiers? This seems... questionably plausible.
> In some cases, alternate methods of verifying the identity may be > used if they provide equivalent or better level of reliability. > This can include e.g. use of national online identification > systems or bank transfers. >
How, exactly, is a bank transfer a better means of establishing ones "legal name as a natural person"?
> c. Verify that the person has access to the corresponding e-mail > address / web resource, e.g. by sending a block of randomly > generated data and requesting sending it back, signed using > the respective key. >
The specific requirement for "randomly generated data" is pointless in any realistic scenario.
> 4. Once you signed a single user identifier of a particular person, you > can sign new user identifiers by just verifying the e-mail address > without repeating identity verification (provided the new UIDs share > the same real name). > > 5. If you have reasons to believe that the particular person has lost > access to the respective e-mail address (e.g. due to retirement), > that the real name is no longer valid or the user identifier became > invalid for any other reason, you should revoke your previous > signature on it. >
Revoking "trust" upon retirement, when the identity would be functionally disabled with respect to Gentoo regardless, seems pointless. Revoking "trust" upon legal name change is logically pointless. Given the recommendation to create and retain a revocation certificate for PGP keys, recommending that "trust" be revoked by others is arguably redundant. [GLEP63]
> > Key signing partners > -------------------- > > In order to improve key signing accessibility to developers, Gentoo will > accept signatures made by members of partner communities. The list > of partner communities will be maintained in Gentoo Wiki [TODO]. New > communities will be added to the list only if they have compatible key > signing rules and they agree to it. >
Even if only for the sake of general example, outside of the proposal itself, there really should be some indication of what "partner communities" are being considered.
> > Example key signing process (informative) > ----------------------------------------- > > Let's consider that Alice is planning to meet Bob and sign his OpenPGP > key. In this section, we will only consider the process of signing > Bob's key from Alice's perspective. Usually, at the same time Bob would > sign Alice's key — with an equivalent process. > > Bob has printed the output of ``gpg --list-keys`` for his key, and gives > it to Alice. It contains the following text:: > > pub rsa2048 2019-01-23 [SC] [expires: 2021-01-22] > 6CDE875E9CCF01D6E5691C9561FB7991B3D45B3C > uid [ultimate] Robert Someone <bob@×××××××.com> > uid [ultimate] Robert Someone <bob2@×××××××.org> > sub rsa2048 2019-01-23 [E] [expires: 2021-01-22] > > Alice verifies the Bob's identity. He gives her his ID card, stating:: > > Given name: Robert > Family name: Someone > > Ideally, Alice would have known what kind of document to expected > and would have read up on verifying it. After verifying that > the document looks legitimate, and the photograph reasonably matches > Bob, she has confirmed Bob's real name. >
Again, this is, according to the supposed "threat model" (ie people who are using false identities and have even the slightest degree of competence in that area) expecting a degree of expertise which is unrealistic.
> Afterwards, she prepares two chunks of random data, e.g. by doing:: > > dd if=/dev/urandom bs=1k count=1 | base64 > > She sends the first of them to ``bob@×××××××.com``, and the second one > to ``bob2@×××××××.com``. Bob replies by quoting the received chunk, > and signing his mail using his OpenPGP key. Once Alice receives > the reply, she verifies the content and the fingerprint of primary key > corresponding to the signature. If they match, she has confirmed Bob's > e-mail addresses. > > At this point, she can sign both of Bob's UIDs. > > > Rationale > ========= > > Milestones > ---------- > > The transitional period is provided so that developers currently missing > user signatures are given time to obtain them. Initially, the period > is set to roughly one and half year but can be extended if the adoption > is problematic. > > Additionally, a half as long transitional period is provided for new > developers. This is meant to avoid blocking recruitment while the key > signing network is still being built. >
Given that Gentoo is perpetually understaffed in various areas, and the single issue that most often comes up as a reason for people to not join and take a more active role is that it involves too much pointless work to get their commit bit set, this proposal seeks to require pointless work which many would out of principle not do and others are simply unable to actually comply with. This seems sub-optimal.
> > Rules > ----- > > The rules aim to reiterate the common web of trust practices. Firstly, > they emphasize the fact that signatures are done per user identifier > and not per key, and therefore each identifier signed needs to be > verified. Appropriately, you don't have to sign all the user > identifiers immediately or at all. > > The policy is focused around standard user identifiers, consisting > of a real name and an e-mail address. In context of those, it requires > at least a single identifier that actually has a real name for GLEP 67
GLEP 76 [GLEP76], GLEP 67 [GLEP67] seems at most tangentially related.
> purposes. It also indicates that there can be other kinds of user > identifiers that may require different verification rules. > > The actual verification of each user identifier consists of confirming > three relevant parts: primary key fingerprint, real name and e-mail > address (or their equivalents in other kinds of user identifiers). > > The primary key fingerprint is used to obtain the correct key to sign, > and to prevent a malicious third party from providing you with a forged > key. Real name and e-mail verification is used to confirm > the authenticity of each user identifier being signed. Use of random > data in e-mail makes it possible to clearly confirm that the same person > is both in possession of the e-mail address and the private keys. >
The randomness in the "random data" is not required to function as claimed, simply using different data, per user, suffices.
> Once an identity is verified once, there is no reason to verify it again > to sign further user identifiers using the same name. This is helpful > e.g. when a person obtains new e-mail addresses, and wishes to get them > signed. In that case, new signatures can be added after verifying > the e-mail address, and confirming match with the prior verified name. >
Functionally, this appear to be counter to point 1, above.
> Finally, since user identifier signatures are normally non-expiring > and therefore indicate perpetual trust, it is reasonable to revoke them > when the identifiers stop being valid. >
Arguably reasonable to recommend, generally pointless in practice.
> > Partner communities > ------------------- > > Both to improve global web of trust coverage, and to avoid requiring > developers to travel abroad to meet other Gentoo developers, the policy > accounts for establishing partnership with other communities using > OpenPGP. Those partnerships will increase the chances that Gentoo > developers and recruits will be able to obtain a valid signature nearer > to their locality. > > In order to maintain a reasonable quality of signatures, only > communities respecting similar rules will be accepted (e.g. verifying > identities of developers). Additionally, the communities will be > contacted first to avoid adding them against their will. > > > Web of trust in other open source projects > ------------------------------------------ > > Debian requires all developers to obtain a signature from at least two > existing developers before joining. They also explicitly note > the necessity of verifying identity. In case it's really impossible to > meet another developer, the Front Desk (equivalent of Recruiters) may > offer an alternative way of identification. [#DEBIAN-IDENTIFICATION]_ > > NetBSD requires all applicants to sign the application with a key that > is already signed by at least one NetBSD developer. [#NETBSD-PGP]_ >
Bother are statements that they have such requirements, neither addresses any benefit from them. As such, this section is pointless.
> > Backwards Compatibility > ======================= > > Gentoo does not use any particular web of trust policy at the moment. > Not all of existing signatures conform to the new policy. Therefore, > approving it is going to require, in some cases: > > a. replacing non-conformant user identifiers, > > b. revoking non-conformant signatures. > > Naturally, those actions can only be carried off by cooperating key > owners. > > The policy specifies transitional periods for developers whose keys are > not signed by anyone in the community yet. >
The policy makes no effort to describe what would happen to developers who, for whatever reason, were not compliant by the end of the proposed transition period. This has been, by multiple people in this thread, inferred to indicate that they will be forcibly retired Leaving what would appear to be fundamental concerns to inference is sub-optimal.
> > Reference Implementation > ======================== > > n/a > > > References > ========== > > .. [#WOT-GRAPH] Gentoo Dev Web of Trust (WoT) > (https://qa-reports.gentoo.org/output/wot-graph.svg) > > .. [#WOT-STATS] WoT Node Stats > (https://qa-reports.gentoo.org/output/wot-stats.html) > > .. [#GLEP76] GLEP 76: Copyright Policy > (https://www.gentoo.org/glep/glep-0076.html) > > .. [#XEP-0373] XEP-0373: OpenPGP for XMPP > (https://xmpp.org/extensions/xep-0373.html) > > .. [#KEYBASE.IO] Keybase > (https://keybase.io/) > > .. [#DEBIAN-IDENTIFICATION] Debian -- Step 2: Identification > (https://www.debian.org/devel/join/nm-step2.en.html) > > .. [#NETBSD-PGP] PGP Key Management Guide for NetBSD developers > (https://www.netbsd.org/developers/pgp.html) > > > Copyright > ========= > This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 > Unported License. To view a copy of this license, visit > http://creativecommons.org/licenses/by-sa/3.0/. > >
[GLEP63] https://www.gentoo.org/glep/glep-0063.html [GLEP67] https://www.gentoo.org/glep/glep-0067.html [GLEP76] https://www.gentoo.org/glep/glep-0076.html